problem in inserting data into database

protected void SubmitButton(object sender, EventArgs e)
{
    SqlConnection conn = new SqlConnection();
    SqlTransaction trans = null;

    conn.ConnectionString = ConfigurationManager.ConnectionStrings["DBMarashi"].ConnectionString;
    SqlCommand cmd = new SqlCommand();
    cmd.Connection = conn;
    conn.Open();

    trans = cmd.Connection.BeginTransaction();
    try
    {
        cmd.CommandText = "INSERT INTO Persons (FirstName,LastName,FatherName,PersonelCode,SerialNumber,NationalNumber,BirthDate_S,PassportNumber,Nationality,Phone,Mobile,PostalCode,Email,HomeAddress) values(@FirstName,@LastName,@FatherName,@PersonelCode,@SerialNumber,@NationalNumber,@BirthDate_S,@PassportNumber,@Nationality,@Phone,@Mobile,@PostalCode,@Email,@HomeAddress)";
        cmd.Parameters.Add("@FirstName", SqlDbType.NVarChar).Value = FirstNameTextBox.Text;
        cmd.Parameters.Add("@LastName", SqlDbType.NVarChar).Value = LastNameTextBox.Text;
        cmd.Parameters.Add("@FatherName", SqlDbType.NVarChar).Value = FatherNameTextBox.Text;
        cmd.Parameters.Add("@PersonelCode", SqlDbType.Int).Value = Convert.ToInt32(personelCodeTextBox.Text);
        cmd.Parameters.Add("@SerialNumber", SqlDbType.Int).Value = Convert.ToInt32(SerialNumTextBox.Text);
        cmd.Parameters.Add("@NationalNumber", SqlDbType.Int).Value = Convert.ToInt32(nationalNumTextBox.Text);
        cmd.Parameters.Add("@BirthDate_S", SqlDbType.Date).Value = Convert.ToDateTime(BirthDateTextBox.Text);
        cmd.Parameters.Add("@PassportNumber", SqlDbType.Int).Value = Convert.ToInt32(PassNumTextBox0.Text);
        cmd.Parameters.Add("@Nationality", SqlDbType.Int).Value = Convert.ToInt32(NationalityTextBox.Text);
        cmd.Parameters.Add("@Phone", SqlDbType.Int).Value = Convert.ToInt32(PhoneTextBox0.Text);
        cmd.Parameters.Add("@Mobile", SqlDbType.Int).Value = Convert.ToInt32(MobileTextBox1.Text);
        cmd.Parameters.Add("@PostalCode", SqlDbType.Int).Value = Convert.ToInt32(PostalCodeTextBox.Text);
        cmd.Parameters.Add("@Email", SqlDbType.NVarChar).Value = (EmailTextBox1.Text);
        cmd.Parameters.Add("@HomeAddress", SqlDbType.NVarChar).Value = (AddressTextBox.Text);

        trans.Commit();
        cmd.ExecuteScalar();
    }
    catch (SqlException se)
    {
        try
        {
            trans.Rollback();
        }
        catch { Page.Title = "SqlException:" + se.Message; }

        try
        {
            trans.Rollback();
        }
        catch (Exception ex)
        {
            Page.Title = "Exception:" + ex.Message;
        }
    }
    finally
    {
        conn.Close();
    }
}